Keep getting:"out of memory" when refreshing?

And most of time it is thrown out by statement:initWidget(uiBinder.createAndBindUi(this)),
but not specific for special class,seems randomly.Generally,this will comes up after refreshing 3 or 4 times,then I must kill jvm then restart;
After upgrade to 2.5 rc1,it will comes up after second time refreshing even first time.And it only happens on refreshing.
   Can anyone give some suggestions to solve this problem?Thanks.